The authors calculate the velocity distribution of halo particles using realistic models for the density profiles of the Galactic disk, spheroid, and halo components. They get the resulting velocity distribution, which is different from the Maxwellian distribution of isothermal halo. The authors investigate the consequences concerning the time averaged count rate and the amplitude of the annual modulation in WIMPs detection experiments. Compared to the previous estimate based on the Maxwellian distribution, the time average count rate is up to 40% larger. On the other hand, the amplitude of the annual modulation is up to a factor of two larger.